function checkform(){
	var uname=document.getElementById("uname").value;
	var pwd=document.getElementById("pwd").value;
	var vcode=document.getElementById("vcode").value;
	var msg="";
	if(uname==""||uname==null){
		msg="用戶名不能為空";
		art.dialog({content:msg,lock:true,ok:function(){}});
		return false;
	}else if(pwd==""||pwd==null){
		msg="密碼不能為空";
		art.dialog({content:msg,lock:true,ok:function(){}});
		return false;
	}else if(vcode==""||vcode==null){
		msg="驗證碼不能為空";
		art.dialog({content:msg,lock:true,ok:function(){}});
		return false;
	}else{
		art.dialog({title:'登陸中...',lock:true});
		return true;
	}
	
}